Table 3.
Acetaldehyde-oxidizing capacities of human, hamster, and rat liver ALDH isozymes
| Source | Isozyme | Acetaldehydeoxidizing capacity, μmol/min per g of liver | Sensitive to daidzin inhibition |
|---|---|---|---|
| Hamster | |||
| Mitochondrial | ALDH-2 | 1.9 | Yes |
| Cytosolic | ALDH-1 | 1.6 | No |
| Cytosolic | ALDH-3 | 0 | No |
| Human | |||
| Mitochondrial | ALDH-2 | 0.43 | Yes |
| Cytosolic | ALDH-1 | 0.02 | No |
| Rat | |||
| Mitochondrial | ALDH-2 | 0.59 | Yes |
| Cytosolic | ALDH-1 | 0.05 | No |
Acetaldehyde-oxidizing capacities of ALDH-1 and ALDH-2 were calculated on the basis of the amounts of each of these isozymes found in freshly prepared liver homogenates, the Km and kcat values determined at pH 7.5 (taken from ref. 6), and an acetaldehyde concentration of 20 μM. The amounts of ALDH-1 and ALDH-2 in these homogenates were determined by the disulfiram titration method using 6-DMA-2-NA as substrate as described (6).